<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src="js/vue.js"></script>
</head>
<body>
<div id="app">
  <select v-model:value="city">
    <option value="beijing">北京</option>
    <option value="shanghai">上海</option>
    <option value="hangzhou">杭州</option>
  </select><br/>
  <h3 v-text="city"></h3>
</div>

<script>
  new Vue({
    el:"#app",
    data:{
      city:"beijing"
    }
  })
</script>
</body>
</html>
